As a key component, a backlight module is mainly used for providing sufficient brightness and uniformly distributed light sources, to enable an LCD panel to normally display images.
FIG. 1 shows a backlight module of an LCD device, including a backplane 100, a lightbar 140 fixed on the side wall of the backplane 100, a reflecting plate 110 arranged on the backplane 100, a light guide panel (LGP) 120 which is arranged on the reflecting plate 110 and opposite to the lightbar 140, a rubber frame 150 and an outer frame 200 which are arranged outside the backplane 100 and used for pressing the LGP 120; optical film(s) 130 is arranged on the light emitting surface of the LGP 120. An LCD panel 300 is fixed above the backlight module by components including the rubber frame 150, the outer frame 200 and the like. The lightbar 140 of such a structure is fixed on the backplane 100. In the inner cavity of the backlight module, the heat emitted by the lightbar 140 is conducted to the surface of the backplane 100 via the side wall of the backplane 100 and then is dissipated through air convection. However, because the heat conduction path is long, the heat is accumulated in the inner cavity of the backlight module for a long time, resulting in certain damage to the components in the backlight module. Thus, the components such as the reflecting plate 110, the LGP 120 and the like in the backlight module operate in a heat accumulating area for a long time and then deform, thereby affecting the stability and the service life of the components in the backlight module as well as the stability of the LCD panel, and reducing the display effect of the LCD device.
As shown in FIG. 2, U.S. Pat. Pub. No. US2010/0002418A1 discloses another backlight module, including a backplane 100, a heat conducting plate 190 closely attached to the backplane 100, a lightbar 140 fixed on the side wall of the backplane 100, an LGP 120 arranged opposite to LED(s) 142 of the lightbar 140, a reflecting plate 110 arranged below the LGP 120, and an outer frame 200 arranged outside the backplane 100; optical film(s) 130 is arranged on the light emitting surface of the LGP 120, and an LCD panel 300 is arranged above the backlight module. In addition, the backlight module further includes a support piece 170 which is used for supporting the reflecting plate 110 and the LGP 120 thereon. Thus, an air cavity 180 is formed between the heat conducting plate 190 and the reflecting plate 110, to play a role of heat insulation. However, although the influence of the heat on the reflection sheet 110, etc. is avoided during heat transfer as far as possible in the arranging mode, the heat conduction path remains that: heat is conducted to the backplane 100 via the heat conducting plate 190, and then dissipated through the contact between the backplane 100 and air. Because the heat conduction path is still long, the heat is accumulated inside the backlight module for a long time, thereby affecting the service life and safety of the components in the backlight module as well as the service life of the LCD panel of the LCD device.